389 research outputs found

    Quality Of Service Enabled Cross-Layer Multicast Framework For Mobile Ad Hoc Networks.

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    Rangkaian ad hoc bergerak merupakan suatu rangkaian tanpa wayar yang boleh dibentuk secara bebas, dinamik serta disusunatur dan ditadbir dalam bentuk topologi rangkaian sementara dan arbitrari. Mobile ad hoc networks (MANETs) are wireless networks that can freely and dynamically be created, organized and administered into arbitrary and temporary network topologies

    Mobile Ad-Hoc Networks

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    Being infrastructure-less and without central administration control, wireless ad-hoc networking is playing a more and more important role in extending the coverage of traditional wireless infrastructure (cellular networks, wireless LAN, etc). This book includes state-of-the-art techniques and solutions for wireless ad-hoc networks. It focuses on the following topics in ad-hoc networks: quality-of-service and video communication, routing protocol and cross-layer design. A few interesting problems about security and delay-tolerant networks are also discussed. This book is targeted to provide network engineers and researchers with design guidelines for large scale wireless ad hoc networks

    Secure Routing in Wireless Mesh Networks

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    Wireless mesh networks (WMNs) have emerged as a promising concept to meet the challenges in next-generation networks such as providing flexible, adaptive, and reconfigurable architecture while offering cost-effective solutions to the service providers. Unlike traditional Wi-Fi networks, with each access point (AP) connected to the wired network, in WMNs only a subset of the APs are required to be connected to the wired network. The APs that are connected to the wired network are called the Internet gateways (IGWs), while the APs that do not have wired connections are called the mesh routers (MRs). The MRs are connected to the IGWs using multi-hop communication. The IGWs provide access to conventional clients and interconnect ad hoc, sensor, cellular, and other networks to the Internet. However, most of the existing routing protocols for WMNs are extensions of protocols originally designed for mobile ad hoc networks (MANETs) and thus they perform sub-optimally. Moreover, most routing protocols for WMNs are designed without security issues in mind, where the nodes are all assumed to be honest. In practical deployment scenarios, this assumption does not hold. This chapter provides a comprehensive overview of security issues in WMNs and then particularly focuses on secure routing in these networks. First, it identifies security vulnerabilities in the medium access control (MAC) and the network layers. Various possibilities of compromising data confidentiality, data integrity, replay attacks and offline cryptanalysis are also discussed. Then various types of attacks in the MAC and the network layers are discussed. After enumerating the various types of attacks on the MAC and the network layer, the chapter briefly discusses on some of the preventive mechanisms for these attacks.Comment: 44 pages, 17 figures, 5 table

    Mobile Ad Hoc Networks

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    Guiding readers through the basics of these rapidly emerging networks to more advanced concepts and future expectations, Mobile Ad hoc Networks: Current Status and Future Trends identifies and examines the most pressing research issues in Mobile Ad hoc Networks (MANETs). Containing the contributions of leading researchers, industry professionals, and academics, this forward-looking reference provides an authoritative perspective of the state of the art in MANETs. The book includes surveys of recent publications that investigate key areas of interest such as limited resources and the mobility of mobile nodes. It considers routing, multicast, energy, security, channel assignment, and ensuring quality of service. Also suitable as a text for graduate students, the book is organized into three sections: Fundamentals of MANET Modeling and Simulation—Describes how MANETs operate and perform through simulations and models Communication Protocols of MANETs—Presents cutting-edge research on key issues, including MAC layer issues and routing in high mobility Future Networks Inspired By MANETs—Tackles open research issues and emerging trends Illustrating the role MANETs are likely to play in future networks, this book supplies the foundation and insight you will need to make your own contributions to the field. It includes coverage of routing protocols, modeling and simulations tools, intelligent optimization techniques to multicriteria routing, security issues in FHAMIPv6, connecting moving smart objects to the Internet, underwater sensor networks, wireless mesh network architecture and protocols, adaptive routing provision using Bayesian inference, and adaptive flow control in transport layer using genetic algorithms

    Mobile Ad Hoc Networks

    Get PDF
    Guiding readers through the basics of these rapidly emerging networks to more advanced concepts and future expectations, Mobile Ad hoc Networks: Current Status and Future Trends identifies and examines the most pressing research issues in Mobile Ad hoc Networks (MANETs). Containing the contributions of leading researchers, industry professionals, and academics, this forward-looking reference provides an authoritative perspective of the state of the art in MANETs. The book includes surveys of recent publications that investigate key areas of interest such as limited resources and the mobility of mobile nodes. It considers routing, multicast, energy, security, channel assignment, and ensuring quality of service. Also suitable as a text for graduate students, the book is organized into three sections: Fundamentals of MANET Modeling and Simulation—Describes how MANETs operate and perform through simulations and models Communication Protocols of MANETs—Presents cutting-edge research on key issues, including MAC layer issues and routing in high mobility Future Networks Inspired By MANETs—Tackles open research issues and emerging trends Illustrating the role MANETs are likely to play in future networks, this book supplies the foundation and insight you will need to make your own contributions to the field. It includes coverage of routing protocols, modeling and simulations tools, intelligent optimization techniques to multicriteria routing, security issues in FHAMIPv6, connecting moving smart objects to the Internet, underwater sensor networks, wireless mesh network architecture and protocols, adaptive routing provision using Bayesian inference, and adaptive flow control in transport layer using genetic algorithms

    On-demand Bandwidth and Stability Based Unicast Routing in Mobile Adhoc Networks

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    Characteristics of mobile ad hoc networks (MANETs) such as lack of central coordination, dynamic topology and limited resources pose a challenging problem in quality of service (QoS) routing. Providing an efficient, robust and low overhead QoS unicast route from source to destination is a critical issue. Bandwidth and route stability are the major important QoS parameters for applications where long duration connections are required with stringent bandwidth requirements for multimedia applications. This paper proposes an On-demand Bandwidth and Stability based Unicast Routing scheme (OBSUR) in MANET by adding additional QoS features to existing Dynamic Source Routing (DSR) protocol. The objective of the OBSUR is to provide QoS satisfied, reliable and robust route for communicating nodes. The scheme works in following steps. (1) Each node in the network periodically (small regular intervals) estimates bandwidth availability, node and link stability, buffer availability, and stability factor between nodes. (2) Construction of neighbor stability and QoS database at every node which is used in route establishment process. (3) The unicast path is constructed by using route request and route reply packets with the help of route information cache, and (4) route maintenance in case of node mobility and route failures. Simulation results show that there is an improvement in terms of traffic admission ratio, control overhead, packet delivery ratio, end to end delay and throughput as compared to Route Stability Based QoS Routing (RSQR) in MANETs.

    Quality of service aware data dissemination in vehicular Ad Hoc networks

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    Des systĂšmes de transport intelligents (STI) seront Ă©ventuellement fournis dans un proche avenir pour la sĂ©curitĂ© et le confort des personnes lors de leurs dĂ©placements sur les routes. Les rĂ©seaux ad-hoc vĂ©hiculaires (VANETs) reprĂ©sentent l'Ă©lĂ©ment clĂ© des STI. Les VANETs sont formĂ©s par des vĂ©hicules qui communiquent entre eux et avec l'infrastructure. En effet, les vĂ©hicules pourront Ă©changer des messages qui comprennent, par exemple, des informations sur la circulation routiĂšre, les situations d'urgence et les divertissements. En particulier, les messages d'urgence sont diffusĂ©s par des vĂ©hicules en cas d'urgence (p.ex. un accident de voiture); afin de permettre aux conducteurs de rĂ©agir Ă  temps (p.ex., ralentir), les messages d'urgence doivent ĂȘtre diffusĂ©s de maniĂšre fiable dans un dĂ©lai trĂšs court. Dans les VANETs, il existe plusieurs facteurs, tels que le canal Ă  pertes, les terminaux cachĂ©s, les interfĂ©rences et la bande passante limitĂ©e, qui compliquent Ă©normĂ©ment la satisfaction des exigences de fiabilitĂ© et de dĂ©lai des messages d'urgence. Dans cette thĂšse, en guise de premiĂšre contribution, nous proposons un schĂ©ma de diffusion efficace Ă  plusieurs sauts, appelĂ© Dynamic Partitioning Scheme (DPS), pour diffuser les messages d'urgence. DPS calcule les tailles de partitions dynamiques et le calendrier de transmission pour chaque partition; Ă  l'intĂ©rieur de la zone arriĂšre de l'expĂ©diteur, les partitions sont calculĂ©es de sorte qu'en moyenne chaque partition contient au moins un seul vĂ©hicule; l'objectif est de s'assurer que seul un vĂ©hicule dans la partition la plus Ă©loignĂ©e (de l'expĂ©diteur) est utilisĂ© pour diffuser le message, jusqu'au saut suivant; ceci donne lieu Ă  un dĂ©lai d'un saut plus court. DPS assure une diffusion rapide des messages d'urgence. En outre, un nouveau mĂ©canisme d'Ă©tablissement de liaison, qui utilise des tonalitĂ©s occupĂ©es, est proposĂ© pour rĂ©soudre le problĂšme du problĂšme de terminal cachĂ©. Dans les VANETs, la Multidiffusion, c'est-Ă -dire la transmission d'un message d'une source Ă  un nombre limitĂ© de vĂ©hicules connus en tant que destinations, est trĂšs importante. Par rapport Ă  la diffusion unique, avec Multidiffusion, la source peut simultanĂ©ment prendre en charge plusieurs destinations, via une arborescence de multidiffusion, ce qui permet d'Ă©conomiser de la bande passante et de rĂ©duire la congestion du rĂ©seau. Cependant, puisque les VANETs ont une topologie dynamique, le maintien de la connectivitĂ© de l'arbre de multidiffusion est un problĂšme majeur. Comme deuxiĂšme contribution, nous proposons deux approches pour modĂ©liser l'utilisation totale de bande passante d'une arborescence de multidiffusion: (i) la premiĂšre approche considĂšre le nombre de segments de route impliquĂ©s dans l'arbre de multidiffusion et (ii) la seconde approche considĂšre le nombre d'intersections relais dans l'arbre de multidiffusion. Une heuristique est proposĂ©e pour chaque approche. Pour assurer la qualitĂ© de service de l'arbre de multidiffusion, des procĂ©dures efficaces sont proposĂ©es pour le suivi des destinations et la surveillance de la qualitĂ© de service des segments de route. Comme troisiĂšme contribution, nous Ă©tudions le problĂšme de la congestion causĂ©e par le routage du trafic de donnĂ©es dans les VANETs. Nous proposons (1) une approche de routage basĂ©e sur l’infonuagique qui, contrairement aux approches existantes, prend en compte les chemins de routage existants qui relaient dĂ©jĂ  les donnĂ©es dans les VANETs. Les nouvelles demandes de routage sont traitĂ©es de sorte qu'aucun segment de route ne soit surchargĂ© par plusieurs chemins de routage croisĂ©s. Au lieu d'acheminer les donnĂ©es en utilisant des chemins de routage sur un nombre limitĂ© de segments de route, notre approche Ă©quilibre la charge des donnĂ©es en utilisant des chemins de routage sur l'ensemble des tronçons routiers urbains, dans le but d'empĂȘcher, dans la mesure du possible, les congestions locales dans les VANETs; et (2) une approche basĂ©e sur le rĂ©seau dĂ©fini par logiciel (SDN) pour surveiller la connectivitĂ© VANET en temps rĂ©el et les dĂ©lais de transmission sur chaque segment de route. Les donnĂ©es de surveillance sont utilisĂ©es en entrĂ©e de l'approche de routage.Intelligent Transportation Systems (ITS) will be eventually provided in the near future for both safety and comfort of people during their travel on the roads. Vehicular ad-hoc Networks (VANETs), represent the key component of ITS. VANETs consist of vehicles that communicate with each other and with the infrastructure. Indeed, vehicles will be able to exchange messages that include, for example, information about road traffic, emergency situations, and entertainment. Particularly, emergency messages are broadcasted by vehicles in case of an emergency (e.g., car accident); in order to allow drivers to react in time (e.g., slow down), emergency messages must be reliably disseminated with very short delay. In VANETs, there are several factors, such as lossy channel, hidden terminals, interferences and scarce bandwidth, which make satisfying reliability and delay requirements of emergency messages very challenging. In this thesis, as the first contribution, we propose a reliable time-efficient and multi-hop broadcasting scheme, called Dynamic Partitioning Scheme (DPS), to disseminate emergency messages. DPS computes dynamic partition sizes and the transmission schedule for each partition; inside the back area of the sender, the partitions are computed such that in average each partition contains at least a single vehicle; the objective is to ensure that only a vehicle in the farthest partition (from the sender) is used to disseminate the message, to next hop, resulting in shorter one hop delay. DPS ensures fast dissemination of emergency messages. Moreover, a new handshaking mechanism, that uses busy tones, is proposed to solve the problem of hidden terminal problem. In VANETs, Multicasting, i.e. delivering a message from a source to a limited known number of vehicles as destinations, is very important. Compared to Unicasting, with Multicasting, the source can simultaneously support multiple destinations, via a multicast tree, saving bandwidth and reducing overall communication congestion. However, since VANETs have a dynamic topology, maintaining the connectivity of the multicast tree is a major issue. As the second contribution, we propose two approaches to model total bandwidth usage of a multicast tree: (i) the first approach considers the number of road segments involved in the multicast tree and (ii) the second approach considers the number of relaying intersections involved in the multicast tree. A heuristic is proposed for each approach. To ensure QoS of the multicasting tree, efficient procedures are proposed for tracking destinations and monitoring QoS of road segments. As the third contribution, we study the problem of network congestion in routing data traffic in VANETs. We propose (1) a Cloud-based routing approach that, in opposition to existing approaches, takes into account existing routing paths which are already relaying data in VANETs. New routing requests are processed such that no road segment gets overloaded by multiple crossing routing paths. Instead of routing over a limited set of road segments, our approach balances the load of communication paths over the whole urban road segments, with the objective to prevent, whenever possible, local congestions in VANETs; and (2) a Software Defined Networking (SDN) based approach to monitor real-time VANETs connectivity and transmission delays on each road segment. The monitoring data is used as input to the routing approach

    A one hop overlay system for Mobile Ad Hoc Networks

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    Peer-to-Peer (P2P) overlays were initially proposed for use with wired networks. However, the very rapid proliferation of wireless communication technology has prompted a need for adoption of P2P systems in mobile networks too. There are many common characteristics between P2P overlay networks and Mobile Ad-hoc Networks (MANET). Self-organization, decentralization, a dynamic nature and changing topology are the most commonly shared features. Furthermore, when used together, the two approaches complement each other. P2P overlays provide data storage/retrieval functionality and MANET provides wireless connectivity between clients without depending on any pre-existing infrastructure. P2P overlay networks can be deployed over MANET to address content discovery issues. However, previous research has shown that deploying P2P systems straight over MANET does not exhibit satisfactory performance. Bandwidth limitation, limited resources and node mobility are some of the key constraints. This thesis proposes a novel approach, OneHopOverlay4MANET, to exploit the synergies between MANET and P2P overlays through cross-layering. It combines Distributed Hash Table (DHT) based structured P2P overlays with MANET underlay routing protocols to achieve one logical hop between any pair of overlay nodes. OneHopOverlay4MANET constructs a cross-layer channel to permit direct exchange of routing information between the Application layer, where the overlay operates, and the MANET underlay layer. Consequently, underlay routing information can be shared and used by the overlay. Thus, OneHopOverlay4MANET reduces the typical management traffic when deploying traditional P2P systems over MANET. Moreover, as a result of building one hop overlay, OneHopOverlay4MANET can eliminate the mismatching issue between overlay and underlay and hence resolve key lookups in a short time, enhancing the performance of the overlay. v In this thesis, we present OneHopOverlay4MANET and evaluate its performance when combined with different underlay routing protocols. OneHopOverlay4MANET has been combined with two proactive underlays (OLSR and BATMAN) and with three reactive underlay routing protocols (DSR, AODV and DYMO). In addition, the performance of the proposed system over OLSR has been compared to two recent structured P2P over MANET systems (MA-SP2P and E-SP2P) that adopted OLSR as the routing protocol. The results show that better performance can be achieved using OneHopOverlay4MANET
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